For travelers who want to get away from the fake blood and costumed zombies this Halloween, there is more authentic experience to be had at Zambia’s Kasanka National Park. The spectacle is said to be the world’s largest mammal migration, with 8 million straw-colored fruit bats arriving from the Congo to eat the wild musuku fruits in the park.

During the migration an overwhelming amount of bats spiral through the skies, screeching and colliding as they return each year to settle in the fruit trees, covering them until there is no longer visible bark. The most memorable time to watch is at sunset, when the bats fly out to find food, creating a thick straw blanket in the sky.

Said Jim Holden, President of African Travel, Inc., in a press release, “The annual migration of millions of bats from the Democratic Republic of the Congo across the border to Kasanka National Park is an astonishing sight. Africa is full of such natural wonders, and most of them are not well known, as with this natural occurrence.”

For a visual idea of the bat migration, check out the gallery below. If you’re interested in seeing the bat migration for yourself, visit the African Travel, Inc. website to book a tour.